Question: Rewrite ${((7^{-9})(5^{-3}))^{10}}$ in the form ${7^n \times 5^m}$.
${ ((7^{-9})(5^{-3}))^{10} = (7^{(-9)(10)})(5^{(-3)(10)})} $ ${\hphantom{ ((7^{-9})(5^{-3}))^{10}} = 7^{-90} \times 5^{-30}} $